Micro-LED has developed into one of the hot spots of future display technology, but its technical difficulties and technical complexity, especially its key technology: massive transfer process. With the development of technology, the development of massive transfer process has produced many technical branches, such as electrostatic adsorption, laser burning, and so on.
The traditional method of transferring a large number of micro LEDs is to transfer the micro-components from the transfer substrate to the receiving substrate by wafer bonding. One of the implementation methods of the transfer method is “direct transfer,” that is, the micro-array array is directly bonded from the transfer substrate to the receiving substrate, and then the transfer substrate is removed. Another implementation method is “indirect transfer.” This method involves two steps of joining/stripping. In the indirect transfer, the transposition head picks up a portion of the micro-element array on the intermediate carrier substrate, then bonds the micro-element array to the receiving substrate, and then removes the transposition head.
However, the current mass transfer processes, whether direct transfer or indirect transfer, are relatively complicated in process and their cost are very high.